Study On The Thermal Environment And Workers’ Thermal Comfort Of Coal Mining Face In High Temperature Mine

With the continuous development of mine mining to the depths,the problem of high temperature heat damage has become increasingly serious,which has become a major problem restricting safe mining in mines.High temperature heat damage not only has a great impact on the efficient and safe production of coal mines,but also seriously threatens the physical and mental health of underground workers.In this paper,taking the thermal environment of the 7302 coal mining face in Zhaolou Coal Mine as the research object,the thermal environment of coal mining face and the thermal comfort of workers were studied by theoretical analysis,field test and numerical simulation.Provide a reference for the management of heat damage in the working face.The thermal conductivity of coal and rock in the coal mining face and the convective heat transfer coefficient between the roadway surrounding rock and air flow were measured;the influencing factors of the thermal environment of the coal mining face were analyzed.The heat dissipation of the surrounding rock and the air leakage of the goaf are two important heat sources that affect the thermal environment of the working face.The influence of the heat exchange between the surrounding rock and the wind flow on the temperature field of the working face was studied.The temperature of the wind flow from the air inlet to the outlet of the working face increases by about 8℃ on average,and the enthalpy value of the wind flow increases greatly after passing though the working face section.Reducing the inlet air temperature can effectively improve the thermal environment of the working face.When the inlet air temperature drops to 24℃,the temperature of the main section of the working face drops to 25～31℃,and the temperature of the return air corner drops to about 34℃.The influence of air leakage and heat dissipation in the goaf on the temperature field of the working face was studied.When the working face is propelled at a speed of 2.4 m/d for 30 days,the temperature in the middle section of the working face and at the return air corner has increased compared with the initial temperature.When the air leakage increases,the hot air in the goaf gushing out to the working face will also increase,and the temperature of the working face will rise.The temperature of the coal and rock in the goaf has a great impact on the temperature field of the working face,the higher the temperature,the more heat carried by the leakage air,and the more obvious the heating effect on the wind flow.Using PMV and PPD as evaluation indicators,the thermal comfort of coal mining face workers under different environmental factors was studied.Temperature has a great impact on human comfort,when the temperature drops from 28℃ to 24℃,the average PMV value of the working face drops from 2.6169 to 1.8569,the average PPD value of the working face at different heights and positions also decreased.Taking the heat damage control of the 7302 coal mining face in Zhaolou Coal Mine as an example,the on-site practice has proved that the thermal environment improvement measures have played a good role in improving the thermal comfort of workers.